Maria Sharapova is reportedly dating Serena Williams’s ex-boyfriend, and the feud between the top female tennis players seems to have stemmed from Williams’s reference to her ex-boyfriend–and Sharapova’s current boyfriend–as someone with a “black heart” in an article published last week.

Williams also reportedly slammed Sharapova as someone who is “boring” and who is “still not going to be invited to the cook parties.”

Sharapova and Williams may battle for the Wimbledon crown in two weeks, and Sharapova’s unusual act of going public to blister Williams over comments she made regarding a Steubenville rape victim in the same article seems to have stemmed from Williams’s unrelated comments in the article about Sharapova and her boyfriend.

In the Rolling Stone interview that was published last week, Williams was quoted as saying this about a fellow player on the Tour:

“There are people who live, breathe and dress tennis. I mean, seriously, give it a rest.” Serena exits the car and the conversation moves on to a top-five player who is now in love. “She begins every interview with ‘I’m so happy. I’m so lucky’ – it’s so boring,” says Serena in a loud voice. “She’s still not going to be invited to the cool parties. And, hey, if she wants to be with the guy with a black heart, go for it.”

The Rolling Stone writer wrote, “An educated guess is she’s talking about Sharapova, who is now dating Grigor Dimitrov, one of Serena’s rumored exes.”

Sharapova snapped back on Saturday, saying, “If she wants to talk about something personal, maybe she should talk about her relationship and her boyfriend that was married and is getting a divorce and has kids.” Her comments were a reference to Williams’s coach Patrick Mouratoglou, the Frenchman with whom Williams has been romantically linked.